Vinyl monomers containing phosphonic acid groups have various applications in industry, for example, their polymer and co-polymers are used as corrosion inhibitor in cooling or boiler water system (U.S. Pat. Nos. 4,446,046 and 4,201,669); as dispersants in water treatment and pigment dispersion. Various type of vinyl monomers were described in prior arts, such as 1-phenylvinyl phosphonic acid (U.S. Pat. No. 5,391,816), vinyl phosphonic acid (U.S. Pat. Nos. 6,479,687, 5,811,575), acrylamidomethylpropanephosphonic acid (U.S. Pat. No. 4,526,788), isopropenyl phosphonic acid (U.S. Pat. No. 4,446,046), chloride substituted phenylvinyl phosphonic acid (U.S. Pat. No. 4,507,249) and diene type of phosphonic acid monomer (U.S. Pat. No. 4,507,249). However, some of those monomers were prepared from very hazardous raw materials of phosphorus chlorides, PCl3 or/and phosphorus acid (H3PO3), or phosphorus hexoxide, (P4O6), or from complicated and expensive processes or/and have limited reactivity toward polymerization.
Recent U.S. Pat. Nos. 7,420,081 and 7,442,831 patents described a new way to prepare some of the above monomers from ketone or aldehyde with phosphorus acid in a mixture of acetic acid and acetic anhydride. These monomers include alkyl and aryl substituted vinyl phosphonic acids of lower reactivity toward polymerization. It is still desirable to have an economic process to produce more reactive phosphonic acid-containing monomers.
In the literature the reactivity of α,β-unsaturated carbonyl compounds has been widely studied and Mauser (Chem. Rev., 1963, 63 (3), pp 311-324) specifically studied the reactivity of mesityl oxide. Typically such compounds can either react at the carbonyl or at the C═C double bond. Usually, the reaction at the carbonyl with strong nucleophilic compounds such as Grignard reagents afford the corresponding hydroxyl adducts or the allenes (1,2-dienes) if the dehydration takes place. When the reactions take place at the double bond with other nucleophilic compounds such as amines or alcohols the mechanism is a 1,4 addition leading to the formation of the corresponding ketone. In particular the reaction of mesityl oxide with dialkylphosphites leads selectively to the formation of the ketones.